Electrical plug-in type contact pins



S. T. DEAKIN ELECTRICAL PLUG-IN TYPE CONTACT PINS March 27, 1962 2 Sheets-Sheet 1 Filed Jan. 15, 1959 smAmE! moms DEAKIN BY ain't 1/ March 27', 1962 s, DEAKIN 3,027,538

ELECTRICAL PLUG-IN TYPE CONTACT PINS Filed Jan. 15, 1959 2 Sheets-Sheet 2 INVENI'OR s'mmy THOMAS DMKIN United States Patent 3,027,538 ELECTRICAL PLUG-IN TYPE CONTACT PINS Stanley Thomas Deakin, Ewell West, Surrey, England, assignor to Siemens Edison Swan Limited, London, England, a British company Filed Jan. 13, 1959, Ser. No. 786,643 Claims priority, application Great Britain Jan. 20. 1958 4 Claims. (Cl. 339-195) This invention relates to electrical plug-in type contact pins and to connectors carrying such contact pins.

The invention has an important application in contacts for insertion along the edge of an insulating board, carrying printed circuitry, to enable the board to be plugged into a multi contact socket holder. It is also applicable to other plug-in connectors on which the contacts are arranged in line.

Plug-in type connectors are of two main types; the first type is that in which the insulation is moulded around the contact pins, the second type is that in which the insulation is first moulded or stamped out of a board with cavities, apertures or slots and spring contact pins are then pressed into the cavities and held there by their resil ience. The invention is concerned with the second type.

Components of this type are produced in large quantities and consequently it is important that they should combine good wearing properties and robustness with ease and cheapness of manufacture.

The main object of the invention is to provide an improved contact pin in which these requirements are satisfied to an appreciable extent.

According to one aspect of the present invention an electrical contact pin for insertion in the edge of an insulating board comprises a strip of electrically conduc tive metal bent about a lateral axis into substantially V- shape having outwardly bowed arms with a longitudinal recess along the outer face of each arm, the arrangement being such that when inserted into a slot extending from the edge of an insulating board insulating edges of the slot will engage the recess so as to locate the pin. Preferably the recesses in the arms terminate in locking apertures.

According to another aspect the invention comprises a plug-in type connector including an insulating board having slots extending from an edge thereof and contact pins as above defined inserted in said slots in such a manner that the edges of the locking apertures overlie shoulders on the sides of the slots and thereby obstruct withdrawal of the pin.

In order that the invention may be more clearly understood reference will now be made to the accompanying drawings in which:

FIG. 1 is a perspective view of a contact pin constructed in accordance with the invention.

FIG. 2 is a side view of the pin shown in FIG. 1.

FIG. 3 is a perspective view of the end of an insulating board carrying contact pins of the type shown in FIGS. 1 and 2.

FIG. 4 shows a board carrying printed circuitry constructed as shown in FIG. 3 and which can be plugged into a socket strip.

FIG. 5 shows one form of socket contact which can be used in the arrangement of FIG. 4.

FIG. 6 shows a locating clip also for use in the arrangement of FIG. 4.

FIG. 7 is a perspective view of a modified form of contact pin.

FIG. 8 is a side view of the pin shown in FIG. 7.

FIG. 9 is a. sectional view on the line IX-IX of FIG. 8.

FIG. 10 shows a modified form of slot in an insulating board.

3,027,538 Patented Mar. 27, 1962 FIG. 11 shows the contact pin of FIG. 7 inserted in the slot shown in FIG. 10, and

FIG. 12 shows a pin of the kind shown in FIG. 1 with a resist applied.

Referring first to FIGS. 1 and 2 the contact pin 1 comprises a metal strip bent about a nose 2 into substantially V-shape so as to form a pair of arms 3 and 4 which are bowed outwardly. As clearly shown in FIG. 2, recesses 5 extend longitudinally down the outer faces of these arms and terminate at their lower ends (i.e. the lower ends in FIG. 1) in apertures 6. The upper ends of the two arms are slotted to form lugs 7..

FIG. 3 shows an insulating board 3 having a series of slots 9 extending from the lower edge 10. The slots 9 have side recesses 11 forming shoulders 12 and an extension 13 at the top end. When a contact: 1 is inserted the two arms are pushed into a slot until the bowed portions are aligned with the recesses 11. The arms will then spring apart so that the shoulders 12 will protrude through the apertures 6 and the edges of the recesses 11 will lie along the recesses 5 to locate the plane of the pin in a direction perpendicular to the plane of the insulating board as shown clearly in the case of the left hand contact of FIG. 3. It will be observed that when inserted the lugs 7 of the pin will extend beyond the extension slots 13, and will overlie the two faces of the insulating board. This will locate the ends 7 of the pins and prevent rocking.

FIG. 4 shows the arrangement in which a plate 8 carrying printed circuitry has a number of contacts 1 along the lower edge 10. These engage sockets 14 in a contact strip 15. These socket contacts may, for example, be of the kind shown in FIG. 5 which again is a U-shaped strip 16 which is pressed into an aperture in the strip 15 so that the flanges abut against the upper face of the strip and the lugs 18 against the lower face of the strip in order to retain it. The contact pins engage resilient arms 20. It will be appreciated that this is only an example of one socket contact which may be employed in connection with the invention and the invention is by no means limited to this type of socket contact.

In order to assist in locating the board 8 (in FIG. 4) longitudinally over the strip 15 locating members 19 may be employed. These are shown in greater detail in FIG. 6 and comprise an upstanding member 21 having a slot 22 into which the vertical edge 23 of the board 8 (FIG. 4) projects. The tag 24 is pushed through the slot in the board 15 and the lugs 25 abut against the under side of the board whilst right angle flanges 26 and 27 rest on the top surface of the board 15 so that the strip is rigidly supported on the board.

The contact pins may be of any suitable resilient conducting metal such, for example, as phosphor bronze. beryllium copper, spring brass or spring steel.

As above mentioned, the invention has an important application in printed circuitry, and in FIG. 3 the reference 28 indicates a printed circuit conductor which, upon dip soldering, makes electrical contact with the lugs 7.

To assist in clamping the pin in place it may also be soldered to an additional printed conductor 29.

FIGS. 7, 8 and 9 show a modified form of contact pin which is generally similar to that shown in FIGS. 1 and 2 but differs in that strengthening ribs 30 are formed along each side of the slot 6; these are dimpled at 31 to permit of engagement by socket contact arms.

Furthermore, additional slots 32 are formed in alignment with slots 6'.

The lower ends have lugs 33 which are bent outwardly. An additional bend 34 is formed in each of the arms 3' and 4'. The pin is intended for insertion in a slot 9' which differs from the slot 9 in that the side recesses 11' are rounded and the entrance has chamfered edges 35 so that the pin can be inserted by a simple push-in operation.

FIG. 11 shows the contact pin inserted in slot 9' in an insulating board 8. It will be observed that the upper shoulders 35 formed by the recesses 11', protrude through the slots 6 Whilst the shoulders 3'1 extend through the slots 32.

In some cases dip soldering processes may be employed and in such cases it may be desired to coat the contacts with a resist to prevent wetting with solder other than the actual contact lugs 7 or within the region of solder point 29.

FIG. 12 shows a contact pin of the kind shown in FIG. 1 with a resist 38 applied to the lower part. Such resists may be applied in the manner described in co-pending application No. 24,208/57.

What I claim is:

1. An electrical contact pin comprising a strip of electrically conductive metal bent about a lateral axis into a substantially V-shape having outwardly bowed arms, the tip of each arm having a parallel side slit defined by a pair of lugs on either side of the slit, and a longitudinal parallel sided recess provided in the outer face of each arm, the slits and the recesses each having the same width and the side surfaces of the slits and of the recesses lying in two parallel planes.

2. An electrical contact pin comprising a strip of electrically conductive metal bent about a lateral axis into a substantially V-shape having outwardly bowed arms, said arms having initial portions which progressively diverge apart and end portions which progressively converge together, the tip of each arm having a parallel sided slit defined by a pair of lugs on either side of a slit, and two longitudinal parallel sided recesses provided respectively in the initial protions and end portions of each arm, the slits and the recesses all having the same width and the side surfaces of both the slits and the recesses lying in two parallel planes.

3. A plug-in connector comprising an insulating board having a plurality of slots extending from the edge thereof, contact pins provided in said slots, said contact pins each comprising a strip of electrically conductive metal bent about a lateral axis into a substantially V-shape having outwardly bowed arms, the tip of each arm having a slit definedvby a pair of lugs on either side of the slit, and a longitudinal recess provided along the outer face of each arm, the slits and the recesses each having a width equal to the width of said insulating board and said lugs contacting opposite surfaces of said insulating board at the ends of the slots to support said pins, and said insulating board including shoulders provided at the side edges of said slots which extend into said recesses to support said pins and to resist removal of said pins from the slots.

4. A plug-in connector comprising an insulating board having a plurality of slots extending from the edge thereof, contact pins provided in said slots, said contact pins each comprising a strip of electrically conductive metal bent about a lateral axis into a substantially V-shape having outwardly bowed arms, said arms having initial portions which progressively diverge apart and end portions which progressively converge together, the tip of each arm having a slit defined by a pair of lugs on either side of the slit, and a pair of longitudinal recesses provided along the outer face of each arm, the slits and the recesses each having a width equal to the Width of said insulating board and said lugs contacting opposite surfaces of said insulating board at the ends of the slots to support said pins, and said insulating board including a pair of shoulders provided at each side edge of said slots which extend into said recesses to support said pins and to resist removal of said pins from the slots.

References Cited in the file of this patent UNITED STATES PATENTS 2,640,970 Falge et al June 2, 1953 2,688,123 Benham et al Aug. 31, 1954 2,832,013 Pedersen et al Apr. 22 1958 OTHER REFERENCES Electronic Industries & Tele. Tech. (publication) by Ruehlemann, October 1956, pages 62, 63, 158, 159, 160, 162. 

